Photocatalytic degradative oxidation of Diuron in organic and semi-aqueous systems over titanium dioxide catalyst

Abstract

The photocatalytic degradation of Diuron in organic and semi-aqueous media is compared. The rates of disappearence fit Langmuir–Hinshelwood kinetics and the parameters k and K have been determined. A main intermediate was detected in all cases and its structure has been determined. This product is obtained by oxidation of a methyl group of the urea moiety. Several compounds [trichloroaniline, dichloronitrobenzene, N-(3,4-dichlorophenyl)formamide, dimethylurea . . .] were detected by GC-MS analysis in both media while hydroxylated compounds were only observed in the semi-aqueous medium.